Ubiquitous access to femto-connected network

ABSTRACT

A system and method of enabling a mobile device to communicate with a local IP network host and an external IP network host using a femto cellular access point on a femto cellular access network. A local gateway is coupled to the femto cellular access network for receiving data packets transmitted on the femto cellular access network and for routing the data packets to one of a local IP network and an external IP network, based on a destination address associated with the data packets. The femto cellular access network includes an LTE network, an EVDO network connected to an EPC, or a WiMax 802.16e/m network connected to the EPC.

FIELD OF THE INVENTION

This invention relates to femto cell networks, and more particularly toa system and method of granting user equipment access to in-homeelectronic devices that are coupled to the femto cell, both while theuser equipment is operating within the femto cell and while the userequipment is operating outside the femto cell.

BACKGROUND OF THE INVENTION

Wireless carriers employ cellular towers to generate large cells forwireless communications over vast physical areas, such as metropolitanor rural areas. The large cells or macro cells may cover areas of 1 kmto 5 km in diameter. A cellular tower broadcasts wireless signals to andreceives wireless signals from user equipment or mobile handsets thatare located throughout the macro cells.

Various structures are located within the macro cell that obstruct,reflect or otherwise interfere with the wireless signals. For example,users typically attempt to use mobile devices inside structures such ashomes and commercial establishments, among other structures. Thesestructures may be constructed of high loss material, such as concrete ormetal that block wireless signals from penetrating the structures.Reception within these structures is often poor and unreliable due toweak wireless signal strength. Poor reception is associated withinferior quality of service by the mobile user. Femto cells or microcells are located within these high loss structures to route signaltransmissions through existing broadband backhaul infrastructure to themacro network. What is desired are systems and methods of allowingmultiple devices, such as cellular and network devices, that are locatedwithin the femto cell to communicate with each other while the userequipment is located within the femto cell or while the user equipmentis located outside the femto cell. Additionally, what is desired aresystems and methods of allowing the user equipment to communicate withhome-based devices, such as data storage devices, printing devices orother devices.

SUMMARY OF THE INVENTION

The invention advantageously provides a method and system for allowingmultiple devices that are coupled through a femto cell, such as userequipment and network terminal devices, to communicate with each otherwhile the user equipment is located within the femto cell or while theuser equipment is located outside the femto cell. The invention alsoallows the user equipment to communicate with home-based devices, suchas data storage devices, printing devices or other devices.

A system is provided for enabling a mobile device to communicate with alocal IP network host and an external IP network host using a femtocellular access point on a femto cellular access network. The systemincludes a local gateway that is coupled to the femto cellular accessnetwork and receives data packets transmitted on the femto cellularaccess network. The data packets are routed a local IP network or anexternal IP network based on a destination address associated with thedata packets.

A system is also provided for enabling a mobile device that is coupledto a macro cellular network to communicate with a local IP network usinga femto cellular access network through a macro cellular access network.A local gateway is provided to receive data packets that are transmittedon the macro cellular access network and to routes the data packets toterminal devices that are coupled to a local IP network.

A method is provided for using a femto cell to facilitate communicationsbetween a mobile device and at least one terminal device. The methodincludes assigning a local internet protocol address to a local gatewayand receiving data packets transmitted by a mobile device at the localgateway. The data packets are analyzed to identify a local destinationaddress and are routed to the at least one terminal device. The datapackets are maintained in a local network without transmitting datapackets to a core gateway.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the invention, and the attendantadvantages and features thereof, will be more readily understood byreference to the following detailed description when considered inconjunction with the accompanying drawings wherein:

FIG. 1 illustrates a block diagram of the an in-home local breakoutnetwork architecture constructed in accordance with the principles ofthe invention;

FIG. 2 illustrates a block diagram of the an away-from-home remoteaccess to a home-based network architecture constructed in accordancewith the principles of the invention;

FIG. 3 illustrates a flow chart for performing a femto cell localbreakout in accordance with the principles of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides femto base stations or home evolved Node-Bdevices that are positioned inside structures to improve cellularquality of service and facilitate communications with devices coupled toa home network. For example, the femto base stations may be positionedinside residential or commercial structures, among other structures. Thefemto base stations may operate in the femto power range of about +l5dBm and may provide an operation range of approximately 50 meters.

The femto base stations communicate with user equipment (“UE”), such ascellular telephone, personal digital assistants, or other UE overwireless cellular technologies. The femto base stations may use existingbroadband backhaul infrastructure to access networks, such as theInternet and/or macro networks, through the publicly-switched telephonenetwork. The femto base stations may be coupled to digital subscriberline (“DSL”) devices or cable modems and to local area networks(“LANs”).

The invention may operate using existing cellular technologies, such asCDMA2000 1xRTT, evolution-data optimized (“EV-DO”) and long-termevolution (“LTE”) networks, among other cellular networks.

The UE 102 may include a wide range of electronic devices, including butnot limited to mobile phones, personal data assistants (“PDA”) andsimilar devices, which use the various communication technologies suchas advanced mobile phone system (“AMPS”), time division multiple access(“TDMA”), code division multiple access (“CDMA”), global system formobile communications (“GSM”), general packet radio service (“GPRS”), 1xevolution-data optimized (abbreviated as “EV-DO” or “1xEV-DO”) anduniversal mobile telecommunications system (“UMTS”). The UE 102 alsoinclude hardware and software suitable to support the control planefunctions needed to engage in wireless communication with the femto basestations and enhanced nodes (“eNB”). Such hardware can include areceiver, transmitter, central processing unit, storage in the form ofvolatile and nonvolatile memory, and input/output devices, among otherhardware.

The invention is directed to deploying a plurality of femto cells withina macro cell environment. While the various femto base stations arecomponents of the overall communications network, each femto cell isseparate and distinct from the existing macro cell and any adjacentfemto cells. During mobility, the system hands UE communication sessionsfrom a femto cell to the macro cell, or vice versa. Alternatively, thesystem may hand UE communication sessions from a femto cell to anotherfemto cell.

According to one embodiment, the macro cells and the femto cells employhandoff procedures that are initiated when signal strength measurementsoriginating in the active network, such as the cellular network or thefemto network, fall below pre-selected threshold parameters. The UE 102may detect the weak signal strength emanating from the “active” accessnetwork and may initiate a handoff to the “idle” access network, such asthe femto base station network or the cellular network, having astronger signal strength, by reporting the weak signal to the activeaccess network.

Alternatively, the handoff procedures may be initiated to off-loadterminal device traffic from the cellular network to the femto basestation network. The femto base station is a personal and dedicated basestation for each corresponding structure, such as a home or commercialbuilding. The femto base stations independently support network traffic,along with the cellular network that supports the macro cell.

The femto base station 110 may be directly or indirectly coupled to ahub/switch 106, DSL/cable modem 107 and/or router 108. These devices mayinclude separate hardware devices or a combination of hardware devices.The hub/switch 106 and router 108 may be provided to share systemresources, such as terminal devices 104, with the UE 102. The terminaldevices 104 may include personal computers, laptops, printers, and mediaplayers, among other terminal devices.

The invention provides femto base stations 110 having a local PDNGateway (“PGW”) 112 with a home access point name (“APN”) and a servinggateway (“SGW”) 114 that directs in-home data requests to terminaldevices 104 that are coupled to a local area network 113. A singleaccess point name may be assigned to a plurality of subscribers and maybe resolved to a target local PGW 112. Alternatively, a plurality ofaccess point names may be assigned to a plurality of subscribers.

Long-term evolution (“LTE”) and evolved high rate packet data (“eHRPD”)are exemplary 4G technologies that improve the universal mobiletelecommunications system (“UMTS”) mobile telephone standard byproviding a simplified, all-packet architecture. The UMTS technologysupports mobile Internet protocol (“IP”) services, such as musicdownloads, video sharing, voice over IP broadband access, and other IPservices to laptops, personal digital assistants (“PDAs”) and otherterminal devices 104. The LTE enhances current UMTS capabilities byproviding improved efficiency, lower costs, increased peak data rates,lower latency, improved services and improved integration with otheropen standards. The invention further supports femto cellular accessnetworks, including an LTE network, an EVDO or evolved high rate packetdata (eHRPD) network connected to an evolved packet core (“EPC”), WiMax802.16e/m connected to EPC.

It should be appreciated that, although the invention is described withreference to the LTE network, the principles of the invention may beadapted by one of skill in the art to include other networks, such asWiMAX (802.16) networks, other CDMA2000 networks and any other networksknown in the art or later developed.

Referring now to the drawing figures in which like reference designatorsrefer to like elements, FIG. 1 illustrates an exemplary block diagram ofa system designated generally as “100” that includes user equipment 102that operates on cellular technology and terminal devices 104 thatoperate on a local area network within a femto cell range. The inventionenables the UE 102 to access the terminal devices 104 that are locatedwithin the femto cell range. The UE 102 may be assigned a local area IPaddress. The femto base station 110 includes a local packet data network(“PDN”) Gateway (“PGW”) 112 having a home access point name (“APN”) anda local serving gateway (“SGW”) 114 that routes in-cell data requests toan in-home LAN 113. The ‘home-based’ PDN or local PGW 112 permits the UE102 to attach to terminal devices 104 on the local area network 113.

Local PGW 112 provides direct connectivity between the UE 102 andterminal devices 104 that are connected to the home LAN 113 through thefemto base station 110. For example, the UE 102 may be directlyconnected to terminal devices 104, including a printer, media player, adisplay device or other terminal devices. The local PGW 112 and thelocal SGW 114 may eliminate the need to send data from the UE 102 acrossto operator's macro network 132. As a result, Internet traffic may beoff-loaded from a service provider's wireless network to the backhaul IPinfrastructure. The femto base station 110, the local PGW 112 and thelocal SGW 114 may be configured to enable the UE 102 to access one ormore packet data networks (“PDN”) concurrently through one or more localPGWs 112.

To support this capability, in addition to supporting a home or localSGW 114 and local PGW 112, the femto base station 110 supports the S5and S11 interface, among other interfaces. The femto gateway (“GW”) 120,in addition to aggregating the S1-MME interface, also may be enhanced tosupport S11 and S5 aggregation.

The femto base stations 110 may include a central processing unit(“CPU”), transmitter, receiver, I/O devices and storage, such asvolatile and nonvolatile memory, to implement the functions describedherein. The femto base stations 110 may communicate with the UE 102 overa radio interface.

The femto base station 110 is coupled to the femto GW 120 through IPsectunnel 116. IPsec tunnel 116 provides a secure public network connectionand preventing wiretapping, traffic manipulation or other securitythreats. The femto GW 120 is an interface to external networks and maybe coupled to a plurality of femto base stations 110. For example, thefemto GW 120 may be coupled to and may manage hundreds or thousands offemto base stations 110. Additionally, the femto GW 120 may beconfigured as an authenticator that grants local breakout authorization.

According to one embodiment, a mobility management entity (“MME”) 134may be provided as a control plane entity to manage the UE 102 withinthe LTE network to authenticate the UE 102. The MME 134 may be connectedto the femto base station 110. The MME 134 is a signaling only entity,such that IP data packets that originate from the UE 102 are notprocessed at the MME 134. The MME 134 may perform various functions,including non-access stratum (“NAS”) signaling; NAS signaling security;tracking area list management for mobile terminals in idle and activemode; packet data network gateway (“PDN-GW”) selection and servinggateway (“S-GW”) selection; roaming; authentication; and bearermanagement functions; among other functions.

The femto GW 120 communicates with packet data network gateway (“PDNGW”) or (“PGW”) 130. The communication may be performed using an S5reference point, among other interfaces. PGW 130 provides the UE 102with access to one or more PDN concurrently through one or more PGWs130. The PGW 130 provides an anchor point for the UE 102 and remains incommunication with the UE 102 throughout a communication session,regardless of whether the UE 102 moves to different network nodes. ThePGW 130 is configured not to receive data that is transmitted using thefemto base station 110 between the UE 102 and in-home terminal devices104. External Internet traffic may be routed to the terminal devices 104through the in-home or local PGW 112 or the PGW 130, based on operatordecision. The PGW 130 may perform various functions, including packetfiltering on a per-user basis; interception; mobile terminal IP addressallocation; uplink (“UL”) and downlink (“DL”) service level charging,gating and rate enforcement; and transport level packet marking in thedownlink; among performing other functions. Additionally, the PGW 130may manage mobility between 4 G networks and non-4 G networks.

A serving gateway (“SGW”) 136 may be coupled to an evolved UMTSterrestrial LAN (e-UTRAN) and the MME 134 to manage packet forwardinguplink and downlink between the PGW 130 and the e-UTRAN environment. TheSGW 136 may perform various functions, including being a local mobilityanchor point for inter-eNB handoffs; mobility anchoring for inter-4 Gmobility; interception; packet routing and forwarding; transport levelpacket marking in the uplink and downlink; uplink and downlink permobile terminal, PDN and quality of service class identifier (“QCI”);and accounting on user and QCI granularity for inter-operator charging;among performing other functions. An IP multimedia subsystem (“IMS”)core 140 may be coupled to the PGW 130 to handle calls or sessions,real-time session negotiation and management. A home subscriber server(“HSS”) may be coupled to the MME 134 to maintain a physical location ofthe user. The HSS may be implemented with a master database havingsubscription and location information.

FIG. 2 illustrates a schematic block diagram of a system for enablingthe UE 102, which is located at a remote location, to communicate within-home terminal 104 devices. The invention enables users to access thehome network 113 while connected to the macro network. Additional PDNconnectivity enables the user to specify a home PDN as a target PDN. TheSGW 136 on the macro network creates an S5 tunnel to the user's home PDNand provides the UE 102 with access to the terminal devices 104 on thelocal network. The components of FIG. 2 are the same as the componentsof FIG. 1, with FIG. 2 including a communications path from the SGW 136to the femto GW 120 in order to facilitate routing of a request to thelocal PGW 112. The UE 102 communicates with the e-UTRAN 135 in the macronetwork, where the UE 102 is authenticated and a data packet isforwarded to the SGW 136. The SGW 136 analyzes the data packet from theUE 102 and determines whether to direct the received data to the localor home-based PGW 112 through the femto GW 120. The UE 102 may acquirean IP address for itself on both the remote network and the local orhome-based network 113 through, for example, a dynamic hostconfiguration protocol (“DHCP”) or another address management protocol.The femto GW 120 may direct the data packets to the local or home-basedPGW 112. The local PGW 112 may send the data packets to the in-home LAN113 for distribution to target in-home terminal devices 104.

FIG. 3 illustrates an exemplary flow diagram for performing localbreakout at the femto base station 110. A femto base station isconfigured to include a home access point name in step S302. Receive adata packet at the macro network in step S304. Evaluate the data packetat the mobility management entity and forward the data packet to thefemto GW at step S306. Forward the data packet to a corresponding localPGW at step S308. Route the data packet to an in-home breakout device atstep S310. Communicate with an in-home device in step S312.

It should be appreciated that, although the invention is described withreference to the LTE network, the principles of the invention may beadapted by one of skill in the art to migrate between any networks,including other networks, such as 1xRTT networks, EV-DO networks, UMTSnetworks, WiMAX (802.16) networks, other CDMA2000 networks and any othernetworks known in the art or later developed.

The present invention can be realized in hardware, software, or acombination of hardware and software. Any kind of computing system, orother apparatus adapted for carrying out the methods described herein,is suited to perform the functions described herein.

A typical combination of hardware and software could be a specializedcomputer system having one or more processing elements and a computerprogram stored on a storage medium that, when loaded and executed,controls the computer system such that it carries out the methodsdescribed herein. The present invention can also be embedded in acomputer program product, which comprises all the features enabling theimplementation of the methods described herein, and which, when loadedin a computing system is able to carry out these methods. Storage mediumrefers to any volatile or non-volatile storage device.

Computer program or application in the present context means anyexpression, in any language, code or notation, of a set of instructionsintended to cause a system having an information processing capabilityto perform a particular function either directly or after either or bothof the following a) conversion to another language, code or notation; b)reproduction in a different material form.

In addition, unless mention was made above to the contrary, it should benoted that all of the accompanying drawings are not to scale.Significantly, this invention can be embodied in other specific formswithout departing from the spirit or essential attributes thereof, andaccordingly, reference should be had to the following claims, ratherthan to the foregoing specification, as indicating the scope of theinvention.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed herein above. In addition, unless mention was made above tothe contrary, it should be noted that all of the accompanying drawingsare not to scale. A variety of modifications and variations are possiblein light of the above teachings without departing from the scope andspirit of the invention, which is limited only by the following claims.

1. A system for enabling a mobile device to communicate with a local IPnetwork host and an external IP network host using a femto cellularaccess point, the system comprising: a femto cellular access network;and a local gateway, coupled to the femto cellular access network, thatreceives data packets transmitted on the femto cellular access networkand routes the data packets to one of a local IP network and an externalIP network, based on a destination address associated with the datapackets.
 2. The system of claim 1, further comprising a femto gatewayprovided at the external IP network, wherein the local gateway sends thedata packet to the femto gateway at the external IP network.
 3. Thesystem of claim 1, wherein the local IP network includes a plurality ofterminal devices.
 4. The system of claim 3, wherein the terminal devicesinclude at least one of a media player, a printer, a computer and a datastorage device.
 5. The system of claim 4, further comprising a routerthat is coupled to the local gateway to communicate with the terminaldevices.
 6. The system of claim 1, wherein the femto cellular accessnetwork includes one of an LTE network, an EVDO network connected to anEPC, and a WiMax 802.16e/m network connected to the EPC.
 7. The systemof claim 1, wherein the local gateway is associated with at least oneaccess point name.
 8. The system of claim 7, wherein a single accesspoint name is assigned to a plurality of subscribers.
 9. The system ofclaim 7, wherein a plurality of access point names are assigned to aplurality of subscribers.
 10. A system for enabling a mobile device thatis coupled to a macro cellular network to communicate with a local IPnetwork using a femto cellular access network, the system comprising: amacro cellular access network; and a local gateway that receives datapackets transmitted on the macro cellular access network and routes thedata packets to terminal devices that are coupled to a local IP network.11. The system of claim 10, wherein the local gateway is a femtocellular access network.
 12. The system of claim 11, wherein the femtocellular access network includes one of an LTE network, an EVDO networkconnected to an EPC, and a WiMax 802.16e/m network connected to the EPC.13. The system of claim 10, wherein the local gateway is associated withat least one access point name.
 14. The system of claim 13, wherein asingle access point name is assigned to a plurality of subscribers. 15.The system of claim 13, wherein a plurality of access point names areassigned to a plurality of subscribers.
 16. The system of claim 10,wherein the terminal devices include at least one of a media player, aprinter, a computer and a data storage device.
 17. A method of using afemto cell to facilitate communications between a mobile device and atleast one terminal device, the method comprising: assigning a localinternet protocol address to a local gateway; receiving data packetstransmitted by a mobile device at the local gateway; analyzing the datapackets to identify a local destination address; routing the datapackets to the at least one terminal device; and maintaining the datapackets in a local network without transmitting data packets to a coregateway.
 18. The method of claim 17, further comprising assigning anaccess point name to the local gateway.
 19. The method of claim 18,further comprising forwarding the data packets to the local gatewayassociated with the access point name.
 20. The method of claim 19,further comprising assigning a single access point name to a pluralityof subscribers.